Which of the following best describes the function of a limit switch?

The function of a limit switch primarily revolves around its ability to detect contact and change an electrical circuit. Limit switches are electromechanical devices commonly used in industrial applications to determine the position of moving parts. When an object physically makes contact with the switch, it activates or deactivates a circuit, allowing for control of machinery and processes. This precise detection of motion or position enhances operational safety and efficiency.

In contrast, the other choices do not accurately represent the primary purpose of a limit switch. While limit switches can be part of systems that involve moving items, stacking, or sorting, their core function is to act as sensors that indicate the presence or absence of an object, thus controlling automation systems based on physical contact.